BOOST (Best Official Off Season Thread) 2013-2014

J'ai finalement ouvert ma transmission pour installer mon nouveau ... quelle déception :(

Ont joue à trouver l'erreur ?

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Jusqu'ici tout va bien ...



Side by side ... ca va encore bien. c'est ici que ça chie:



Le diff était supposé être un kaaz pour B18c et j'ai reçu un diff pour B16a. Le diamètre intérieur de la final drive est 7mm plus petit :yikes:

Au moins le vendeur n'a pas gossé et il va le reprendre *tu*
Du coté positif, ça ma permit d'inspecter ma transmssion avant la prochaine saison !

Comme j'étais frustré de n'avoir rien fait de productif, j'ai décidé de swappé mes coils Avant/Arrière.
Le setup était 500/400 et le cul n'était pas assez loose à mon goût.

J'ai hâte de voir si ça va faire une grosse différence une fois inversé pour 400/500.



Sinon, je pense remettre les 500 en avant et acheté des 700 ou 800 pour derrière.
 
No I don't but I do know I plan on running 700lbs springs and had to order revalved koni's as suggested by Ground Control.
 
^^ good to know !

How much do they charge to revalve them ? It could be difficult with HKS, I think they disappeared from North America by now ...
 
Gregster said:
No I don't but I do know I plan on running 700lbs springs and had to order revalved koni's as suggested by Ground Control.
Click to expand...

I tried a couple of sets of GC on E46 M3 with stiff springs and it was ok. The 2002 jet black I bought from Martin H. was on 700f/800r GC track/school coilovers if I remember correctly. Even my KW Clubsport on my Coupe are supposed to be design for rear progressive springs and I have 650f/750r spring rate. I would not pay the extra $$$ for revalving.
 
Good schock valving is crucial IMO. I've had terrible experience with KONI but wonderful with Bilstein. As for going stiff.... don't go overboard cause remember, you might need to drive the car in the rain as well. Aim for a good compromise. Just sayin'
 
Gregster said:
will those HKS even handle 700-800lbs on the current valving?
Click to expand...

MycHo said:
Honestly I'm not sure ... Haven't looked into it yet. I'll try them as is first.
Do you have personal experience with them ?
Click to expand...

Black VW said:
Good schock valving is crucial IMO. I've had terrible experience with KONI but wonderful with Bilstein. As for going stiff.... don't go overboard cause remember, you might need to drive the car in the rain as well. Aim for a good compromise. Just sayin'
Click to expand...

Hey, I thought I would pitch in to give a few tips with stiffer springs!

All shocks have more damping in rebound than in compression, this is because when the wheel is in compression, part of the energy is dissipated in the shock absorber and the rest is accumulated in the spring by compressing it.

In rebound, think of a sudden extension, the shock has to damp ALL of the energy that has been accumulated in the spring by controling it's retraction. Therefore the damping needs to be higher.

here is a force VS speed curve for a shock:
Rebound below, compression top,
Force on the vertical axis, shock speed on the horizontal axis
13-16200-front.jpg


So if you do run stiffer springs on the same shocks, chances are that you will have to REDUCE compression damping, bceause the stiffer spring can accumulate more energy, therefore the shock needs to do less.

You'll need to INCREASE rebound damping, because the shock has to control all the energy that has been accumulated in the stiffer spring.

So, if you want to run stiffer springs, make sure you have enough adjustability range on rebound damping or the car could become stiff and bouncy :p


To give you an example: on the cars I work on we have 10 different setups for compression damping that cover ALL the springs we use during the season.
However, we have 45 (yes 45) different suspension configurations just to cover the rebound damping for all the springs.
 
oldschoolZ said:
Hey, I thought I would pitch in to give a few tips with stiffer springs!

All shocks have more damping in rebound than in compression, this is because when the wheel is in compression, part of the energy is dissipated in the shock absorber and the rest is accumulated in the spring by compressing it.

In rebound, think of a sudden extension, the shock has to damp ALL of the energy that has been accumulated in the spring by controling it's retraction. Therefore the damping needs to be higher.

here is a force VS speed curve for a shock:
Rebound below, compression top,
Force on the vertical axis, shock speed on the horizontal axis
13-16200-front.jpg


So if you do run stiffer springs on the same shocks, chances are that you will have to REDUCE compression damping, bceause the stiffer spring can accumulate more energy, therefore the shock needs to do less.

You'll need to INCREASE rebound damping, because the shock has to control all the energy that has been accumulated in the stiffer spring.

So, if you want to run stiffer springs, make sure you have enough adjustability range on rebound damping or the car could become stiff and bouncy :p


To give you an example: on the cars I work on we have 10 different setups for compression damping that cover ALL the springs we use during the season.
However, we have 45 (yes 45) different suspension configurations just to cover the rebound damping for all the springs.
Click to expand...

Very interesting .
Thanks for sharing your knowledge !
 
oldschoolZ said:
You'll need to INCREASE rebound damping, because the shock has to control all the energy that has been accumulated in the stiffer spring.

So, if you want to run stiffer springs, make sure you have enough adjustability range on rebound damping or the car could become stiff and bouncy :p
Click to expand...

Thanks for the tip Oldschoolz *tu*

unfortunately, my shocks don't have separate adjuster for Damping and Compression. But from reading on the web, I saw that the single adjuster (30 clicks located on top of the shock) is supposed to adjust BOTH at the same time !?!? If this is the case, the only way I can increase rebound is to increase compression as well ...

I calculated my effective wheelrate from swapping coils front to back (used ratio--> Front:1.5, Rear:1.35):

Before (500F/400R)

Front --> 224
Rear --> 215

After (400F/500R)

Front --> 174
Rear --> 276

In the end, I don't think this change is gonna do much to help my car rotate around tight corners.
And according to Pat who already tried 400 in the front, it might not be enough .... Decision-Decision
 
... and also most serious outfits will tell you not to spend your money on adjustable stuff unless you pay top dollar because of strong variances between each shock when adjusted at the same setting. So, spend once on good non adjustable correctly engineered set up once.... and live with it.

My 5c
 
Gregster said:
What are you using for alignment specs? How big of a rear bar?
Click to expand...

last year specs were:

camber --> -2.5 Front, -2.0 Rear
Toe --> 0 Front (didn't liked toe out in front), a hair of toe out for the rear

I'll go larger on tires this year, so I worried that rotation would get worst with the extra grip in the rear.
I'll have to play with the setup to find what I like ... sounds like Fun !
 
Since we are discussing suspension set ups . Here's what I will be running this season . JRZ RS 2 way with 800lbs - 900lbs Hyperco springs . Major upgrade from my Tein SSPs :run:

 
With all that, you may end up learning to like toe out in front. at least 1/32 or 1/16.

MycHo said:
last year specs were:

camber --> -2.5 Front, -2.0 Rear
Toe --> 0 Front (didn't liked toe out in front), a hair of toe out for the rear

I'll go larger on tires this year, so I worried that rotation would get worst with the extra grip in the rear.
I'll have to play with the setup to find what I like ... sounds like Fun !
Click to expand...
 
MycHo said:
Thanks for the tip Oldschoolz *tu*

unfortunately, my shocks don't have separate adjuster for Damping and Compression. But from reading on the web, I saw that the single adjuster (30 clicks located on top of the shock) is supposed to adjust BOTH at the same time !?!? If this is the case, the only way I can increase rebound is to increase compression as well ...

I calculated my effective wheelrate from swapping coils front to back (used ratio--> Front:1.5, Rear:1.35):

Before (500F/400R)

Front --> 224
Rear --> 215

After (400F/500R)

Front --> 174
Rear --> 276

In the end, I don't think this change is gonna do much to help my car rotate around tight corners.
And according to Pat who already tried 400 in the front, it might not be enough .... Decision-Decision
Click to expand...

Your calculations are correct, assuming the motion ratios are good !

If your shocks adjust compression and rebound at the same time, my guess is that the gain in rebound damping would be geater than the gain in compression for every click. I've never used single-adjustable shocks, but I would think they would keep the same ratio between compression and rebound damping as you increase/decrease the clicks.

FWD touring cars i've worked on ran softer wheelrates in the front than in the rear, combined with a low roll-center in the front and very stiff rear anti roll bar. On a short wheelbase car, the softer rates and low roll-center in the front will make the front corner dip down and the inside rear wheel lift off the ground.

We deliberatly did this because almost all racing series require you to run the same tire size all around. If you have the same tires all around on a heavily front-biased car like a touring car, you end up with more grip proportionaly in the rear than in the front, leading to understeer.

So, to adjust the under/oversteer balance we would deliberatly make the rear inside wheel lift off the ground, run lots of camber, high tire pressures and VERY stiff anti roll bars in the rear to ''remove'' or ''kill'' grip in the rear.

Since you don't race and are not required to comply to any rules, you can also run a narrower tire in the rear, which would save you money, but you couldn't rotate the tires mid-season...

Hope that helps !

MycHo said:
last year specs were:

camber --> -2.5 Front, -2.0 Rear
Toe --> 0 Front (didn't liked toe out in front), a hair of toe out for the rear

I'll go larger on tires this year, so I worried that rotation would get worst with the extra grip in the rear.
I'll have to play with the setup to find what I like ... sounds like Fun !
Click to expand...

Toe out in the front will definitely help you for initial turn in, however it's the car becomes very unstable to side winds and cracks in the racetrack. If you just align the car once for the whole season regardless of track conditions I wouldn't run toe out because it'll be a disaster in the rain (so responsive in fact that you'll end up in the wall quite quickly :p )
 
oldschoolZ said:
Your calculations are correct, assuming the motion ratios are good !
Click to expand...

I used motion ratios found on the web, might not be perfect but still close enough for me as a comparison tool.

oldschoolZ said:
FWD touring cars i've worked on ran softer wheelrates in the front than in the rear, combined with a low roll-center in the front and very stiff rear anti roll bar. On a short wheelbase car, the softer rates and low roll-center in the front will make the front corner dip down and the inside rear wheel lift off the ground.
Click to expand...

That was exactly my goal by doing the front to rear swap, the low-cost solution was to re-use the same coils.


oldschoolZ said:
Toe out in the front will definitely help you for initial turn in, however it's the car becomes very unstable to side winds and cracks in the racetrack. If you just align the car once for the whole season regardless of track conditions I wouldn't run toe out because it'll be a disaster in the rain (so responsive in fact that you'll end up in the wall quite quickly :p )
Click to expand...

You're right ... I usually don't change my alignment during the summer. I'll probably keep 0 toe, add some neg camber to accommodate the 225 RS3 and maybe change my rear bar from a 22mm to a ASR 24mm. Like you said, no racing here ... Just tons of fun playing with our toys at the track :D
Thanks a lot for your post, very good info *tu*
 
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